Automatic trip and reset mechanism



Jan. 4, 1966 a. a. PASQUINELL 3,227,031

AUTOMATIC TRIP AND RESET MECHANISM Filed Sept. 22 1961 2 Sheets-Sheet I FIG.2

' INVENTOR.

BRUNO B. PASQUINELLI BY 64 naw/W W Jan. 4, 1966 a. B. PASQUINELL AUTOMATIC TRIP AND RESET MECHANISM 2 Sheets-Sheet 2 Filed Sept. 22 1961 FIG. 4

INVENTOR.

BRUNO B. PASQUINELLI United States Patent 3,227,981 AUTOMATIC TRIP AND RESET MECHANISM Bruno B. Pasquinelli, Evergreen Park, Ill., assignor to Miehle-Goss-Dexter, Incorporated, Chicago, 1th, a corporation of Delaware Filed Sept. 22, 1961, Ser. No. 140,094 11 (Claims. (til. 101-284) The invention relates to trip mechanism for printing presses and has reference more particularly to an automatic trip mechanism for stopping the press upon failure of a sheet to be delivered for printing, and which additionally incorporates means for automatically resetting the trip in the event it is manually rendered inoperative.

The invention is concerned with that type of printing press wherein the type bed has reciprocating movement in a vertical direction and wherein the impression cylinder is supported for rotation so as to coact with the bed in the printing of sheets delivered to the cylinder. On the downstroke of the bed the cylinder rotates for a printing impression and simultaneously therewith the oscillating delivery arms move in to take the printed sheet. On the upstroke of the bed the impression cylinder is off impression and the cylinder does not rotate. Sheet detecting means are provided which will detect the presence or absence of a sheet or an improperly registered sheet before the impression cylinder is rendered operating for printing. In the absence of a sheet or improper registration of a sheet the impression cylinder is not rendered operative and it does not rotate on the next downstr-oke of the bed. The trip mechanism of the invention is coordinated with the rotating movements of the cylinder to trip and stop operation of the press following a failure of the impression cylinder to initiate a printing operation.

An object of the invention resides in the provision of trip mechanism for a printing press of the type as described which will be actuated by means having movement during the printing operations of the press produced partly by the oscillating delivery arms and partly by the rotations of the impression cylinder.

Another object is to provide trip mechanism which when actuated will release the control shaft for the print ng press, thereby permitting its return for stopping the press and wherein the trip mechanism is actuated due to the fact that the rotations of the impression cylinder fail to take place.

Another object of the invention is to provide trip mechanism of the character described which will operate automatically to trip the press upon failure of a sheet to be delivered for printing, and which will incorporate additional means adapted to be manually actuated whereby the operator can render the trip mechanism inoperative.

Should the operator at any time inadvertently leave the trip mechanism inoperatively positioned and should the operator then start operation of the press for normal printing, the invention provides means for automatically resetting the trip mechanism as a result of press operation thereby rendering the trip mechanism again operative for performing its tripping function.

With these and other objects in view, the invention may consist of certain novel features of construction and operation, as will be more fully described and particularly pointed out in the specification, drawings and claims appended thereto.

In the drawings:

FIGURE 1 is a side elevational view showing one embodiment of the trip and reset mechanism of the invention, with the elements being shown in the position they may assume during normal printing operations;

FIGURE 2 is a sectionai view substantially along line 22 of FIGURE 1, showing the control shaft and handle 3,227,081 Patented Jan. 4, 1966 with friction locking means for controlling the starting and stopping of the press and its operating speed;

FIGURE 3 is a sectional view on a somewhat enlarged scale taken substantially along line 3--3 of FIGURE 2;

FIGURE 4 is a sectional view showing the manually actuated release member for rendering the trip mechanism inoperative;

FIGURE 5 is an elevational view showing the elements of the trip mechanism as in FIGURE 1 and which illustrates in diagrammatic form their mode of operation; and

FIGURE 6 is a fragmentary elevational view of the trip mechanism as shown in FIGURE 5 with the positionable control bar in a latched position for illustrating the action of the trip resetting means.

In the drawings the invention is disclosed as applied to a vertical type of printing press wherein the main frame of the press has mounted the reciprocable type bed 10 and the rotatable impression cylinder 12. The bed carries the type form such as 13 and the said impession cylinder is suitably jou-rnalled by the shaft 14. The bed 10 s adapted to reciprocate but it coacts with the impression cylinder 12 only on the downward stroke of the bed. The reciprocating movement is produced by the connecting elements, including the connecting rod 15 having connection with the bed at 16. On the upstroke of the bed the impression cylinder is off impression and coac'tion between the two printing elements does not take place. Accordingly, the impression cylinder will have rotation on the downstroke of the bed for a printing operation, but will remain stationary on the upstroke of the bed.

The delivery arms 18 are fixed to and oscillated by the delivery arm shaft 20 for movement in coordinated relation with the type bed so that as the bed moves down the arms move toward the right (FIGURE 1). At the completion of the downstroke the bed is in its lowest position and the impression cylinder is at rest. In coordinated relation therewith, the arms 18 move across the type bed and the grippers 21 coact with the impression cylinder for gripping and removing a printed sheet from the grippers 22 of the cylinder.

The impression cylinder 12 is provided with sheet deteot-ing means which operate to detect the presence or absence of a sheet on the cylinder immediately before the cylinder is rendered operative for a printing operation. Thus, upon failure of a sheet to be fed to the cylinder for printing purposes the cylinder is stopped and the same does not rotate as the bed moves down for its printing stroke. The fact that the impression cylinder rotates on a printing stroke and remains at rest in the absence of a sheet being fed thereto for printing or in the event of improper registration, is utilized by the invention to actuate the trip mechanism for tripping and stopping operation of the printing press. For this purpose, the shaft 14 is provided with the eccentric 23 and the collar 24 encircling the eccentric is connected to one leg of the bell crank lever 25 by the rod 26. The lever 25 is journalled at 27 for oscillating movement and the other leg of the lever is connected at 28 to a connecting rod 30, which is pivotally joined at 31 to the link 32. The link is in turn actuated by the delivery arm shaft 20 since the link is pivoted at 33 to the member 34 suitably fixed to the shaft 20. The joint at 28 is such as to permit lost motion of the rod 30. A block 35 of suitable configuration is pivoted to the bell crank lever and the rod passes through the block having the cap nut 36 fixed to its project-ing end and having the coil spring 37 located below the block. Thus, the coil spring 37 isconfined between the block and a pin and washer combination 38. The rod 30 is moved in an up direction by clockwise oscillation of the bell crank lever 25 and should the rod be held against movement on counterclockwise rotation of the bell crank lever, such ac- 3 tion will take place against the tension of the coil spring 37.

From the foregoing it will be observed that the link 32 has compound movement, being partly produced by the oscillations of the bell crank lever and partly by the oscillations of the delivery arm shaft 20. The invention is particularly concerned with the right hand end 49 of the link 32 and with the terminal end 41 of the rod 30. The end of the link and the terminal end 41 of the rod coact respectively with the trip lever 44 and with the positionable control bar 42, which structure will now be described.

The positionable control bar 42 is pivoted to the frame of the press at 45 and the opposite free end of the bar is normally supported by the pin or stud shaft 46 fixed to and projecting from the frame. The trip lever 44 is operatively associated with the positionable control bar 42, being journalled at 47 for oscillating movement and having a part 48 normally extending above the bar and also a part 50 normally having contact with the stud shaft 46. The stud shaft acts as a stop limiting movement of the trip lever 44 in a counterclockwise direction. Actually, the stop portion 56 of the trip lever 44 is yieldingly held in contact with the stud shaft 46 by the coil spring 51. Said spring is fixed to the trip lever at 52 and to a pin 53 on the lever 42, and thus the spring also serves to yieldingly hold the lever 42 against the stop 46.

The trip end 54 of the trip lever is arcuate in formation, as will be seen from FIGURE 3, and the same is bifurcated to provide two such arcuate arms for operative coaction with the yoke 55, the arms straddling the yoke and being located underneath the pin 56 so as to contact the pin which is fixed to the yoke and extends transversely thereof. The yoke is connected to the rod 57 and is pivoted at 58 to an extension of the control handle 61). Said handle 60 is pivoted at 61 to the handle support and control lever 62 which is mounted on and fixed by the hub 63 to the start-stop and speed control shaft 64, the said shaft in turn controlling the driving motor for the printing press and which starts and stops the motor and has intermediate positions for various speeds.

Releasable locking elements are associated with shaft 64 for which purpose the shaft is provided with flat sides 65. On this portion of the shaft there are located a plurality of friction discs 66, which are held on the shaft in a manner whereby the flat sides 65 prevent their rotation. Friction discs 67 alternate with the discs 66 and said discs 67 are non-rotatably held by the collar '68 which is supported by and forms a part of the press frame. The pressure plate '70 is freely carried by shaft 64 and the left hand ends of the levers 71 (FIGURE 2) are adapted to engage the pressure plate and force the plate in a direction towards the left into pressure contact with the arrangement.

of friction discs. The levers 71 are pivoted at 72 to the bifurcated arms 73 of the yoke 55 and the right hand ends of the levers are mounted in a pivot recess provided by the hub 63 of the control lever and handle support 62.

It will be understood that the shaft 64 is spring biased into a stop position for stopping operation of the printing press. Accordingly, with the friction locking elements 66 and 67 released, the shaft will automatically move into such s-top position to stop the press. In order to release the friction locking elements the operator grips the handle 60 and moves the same in a down direction. This motion will lift the yoke 55 and the levers 71 will pivot on hub 63 in a clockwise direction. The left hand end of the levers 71 will thus move out of contact with the pressure plate 76 and the friction discs are thus released. With the handle in a down or approximately horizontal position, the operator can start operation of the press or he can vary the speed of the press by rotating the shaft 64 in the proper direction. For a stop or full-speed position or for any intermediate position, it will be appreciated that the shaft 64 can be locked in said position by merely elevating the handle 60. The same applies pressure on the friction locking elements thereby holding the shaft in the selected position.

During operation of the printing press the positionable control bar 42 is located as shown in FIGURES 1 and 2. As the cylinder 12 rotates on a printing stroke of the reciprocal bed 10 and the delivery arms 18 move in to take the printed sheet, it will be seen that the pivot 31 has compound movement caused partly by the movement of the link 32 in a direction towards the right and partly by movement of the rod 30 in the upward direction. The various positions which the pivot 31 and the pin 29 assume during a printing operation are illustrated in FIG. 5. The result of the compound movement of the several parts is to cause such motion of the end 40 of link 32 that the end does not contact the projecting part 48 of the trip lever. The trip lever is thus not actuated and the press continues to operate under the control of the operator.

In the event a sheet is not presented to the cylinder 12, or if a sheet is improperly registered, the sheet detecting means for the cylinder will trip the same olf impression and for the next downstroke of the bed the cylinder will remain stationary. Under these conditions the rod 30 also remains stationary and the end 40 has movement only in a righthand direction, caused by the delivery arm shaft 20. Accordingly, the end 40 will eventually contact the projecting part 48 and in so doing the trip lever 44 is rocked in a clockwise direction. The trip end 54 is correspondingly elevated, and since the end 54 has contact with the pin 56, the yoke 55 is also elevated to release the friction locking elements 66 and 67. With said elements released, the control shaft is also released and the same automatically returns to a stop position since it is spring energized to move in this direction. The press is accordingly brought to a stop and press operation can be resurned again only by a positive act of the operator.

The actuation of the trip lever 44 in accordance with the invention is thus coordinated with the rotations of the impression cylinder. During operations of the press, the link 32 will always have reciprocating movement in a direction approximately horizontal and parallel to the control bar 42. However, its movement in an upward direction is dependent on the rotations of the impression cylinder 12 and when the cylinder is tripped off impression the action of the link 32 is to trip the lever 44 and stop operation of the press.

For make-ready, inking up and for other preliminary operations of the press during which no sheets are fed to the impression cylinders, the operator may desire to render the tripping mechanism inoperative. For this purpose the invention provides a manually actuated re lease rod 75 and pin 76 for engaging and elevating the control bar 42. The pin 76 and a knob 77 are fixed to the rod and said rod is mounted at 78 for rotation in the frame of the press, all as shown in FIGURE 4. When the positionable control bar 42 is elevated by the manual release, it will be seen that the bar has a position above the part 48. Thus, when the press is operated the end 40 the link 32 cannot contact the trip part 48 of the trip lever even though the impression cylinder will remain stationary during reciprocating movement of the type bed 10 in a printing direction. When the operating means for the trip mechanism are rendered inoperative the press will not trip and the same will continue to run as long as the control bar is located and held above the trip part 48.

FIGURE 6 shows the control bar 42 in elevated position to render the actuating means inoperative. Under these circumstances the end 40 of link 32 will continue to move back and forth substantially parallel to the top surface of the control bar, but said end 46 will not move up and down, since no sheets are being fed and the impression cylinder 12 does not rotate. When such motion takes place and the bar 42 is elevated as in FIGURE 6, the end 41 will contact and ride on bar 42. Under these conditions the pivot point 31 will travel in substantially a straight path and any resultant raising movement of the rod 30 will be absorbed by the coil spring 37.

In the event the operator should start operation and begin to feed sheets to the press for regular printing while leaving the control bar 42 in elevated trip-release position, the invention provides means for resetting the control bar and which is automatic, being effected by the printing operations of the press. The trip resetting means as shown in FIGURES l, 5 and 6 essentially consist of crescent shaped member 86 which is pivoted at 81 to a straight pivot member 82 which is pivoted on the frame at its upper end at 83. The lower free end of the member 82 is recessed at 84 and the Width and depth of the recess is such as to receive the adjacent end of the control bar 42. The recessed end of the member 82 is yielding biased towards the end of the control bar by the coil spring 85, see FIGURE 1, which is fixed at its opposite end to the pin 53.

The recess 84 receives the end of the control bar when the bar is elevated by the manual release pin 76 and thus independently of the release means the positionable control bar is held by the pivot member 82 in release position. In the event the operator should start operation of the printing press for regular printing operations and should the control bar 42 be left in elevated position, the crescent shaped member 80 is operative to automatically reset the control bar. This operation is. accomplished by the pin 29 and by the member 80 which is especially shaped at 86.

In FIGURE 5 it will be. noted that when the trip mechanism is set for normal operation the lower end of the crescent shaped member rests against the shaft 46. Thus, when the pivot member 82 is in 'its release or inoperative position, the end 86 of the crescent shaped member is maintained out of the path of the pin 29.

When the pivot member 82 is in latching position as in FIGURE 6, the pivot point 81 of the crescent shaped member is moved to the left, thereby causing the end 86 of the member to drop into the path of the pin 29. Consequently, if the trip mechanism is left in this inoperative position by the operator after the make-ready procedure is completed, and should he commence to feed sheets to the press, the crescent shaped member will function to automatically reset the trip mechanism for automatic operation.

As the first sheet reaches the impression cylinder, the the cylinder will be caused to rotate on a normal printing operation. This, in turn, will rotate the bell crank 2-5 and upon upward movement of the rod 3%, and thus the pin 2h, and with movement of the parts in a right hand direction due to rotation of the shaft 2%, thepin 29 will eventually contact the shaped end 86 of the crescent shaped member 80 as illustrated in FIGURE 6. This contact is suificient to move the member 82 towards the right and the member accordingly releases the control rod 42 which drops under the influence of the spring 51 to an operative position in contact with the stud shaft 46.

The invention is not to be limited to or by details of construction of the particular embodiment thereof illustrated by the drawings, as various other forms of the device will, of course, be apparent to those skilled in the art without departing from the spirit of the invention or the scope of the claims.

What is claimed:

1. In a printing press of the class having an intermittently rotating impression cylinder and an oscillating delivery arm shaft, the combination including a pivoted trip lever yieldingly held against a stop preventing rotation of the trip lever in one. direction, a trip arm provided by the lever and having movement when the lever is rocked in an opposite direction, a control shaft for starting and stopping the press and for controlling press speed, said control shaft being spring tensioned into a stop position, friction means for locking the control shaft in selected positions when rendered operative and for releasing the control shaft from its selected position when the friction means is released, manual means for locking and releasing the friction means, said trip arm having association with the manual means in a manner to effect release of the friction means when the trip lever is rocked in said opposite direction, actuating means responsive to non-rotation of the impression cylinder for rocking the trip lever in said opposite direction, means operatively connecting the actuating means with the impression cylinder and with the delivery arm shaft, whereby said actuating means has compound movement during printing operations of the press, said compound movement being produced partly by the oscillation of the delivery arm shaft and partly by the rotation of the impression cylinder, and whereby said actuating means is operative to contact and rock the trip lever in said opposite direction should the impression cylinder fail to rotate during an operation which could otherwise constitute a printing. operation.

2. In a printing press, the combination as defined by claim 1, wherein the friction means includes a plurality of friction discs non-rotatably fixed on the control shaft and a plurality of similar friction discs non-rotatably fixed to the press frame and encircling the control shaft in alternate relation to said first mentioned discs, and additionally including a pressure plate also encircling the control shaft, said pressure plate having a position for locking the control shaft when in pressure engagement against the friction discs, and "said pressure plate having a position for releasing the control shaft when out of pressure engagement with the friction discs.

3. In a printing press, the combination as defined by claim 1, wherein the actuating means includes a link connected to and reciprocated by the oscillating delivery arm shaft, and a rod pivotally joined to the free end of the link and connected to and reciprocated by the rotations of the impression cylinder, said link and rod being disposed approximately at right angles to each other.

4. In a printing press of the class having a vertically reciprocable type bed, an intermittently rotating impression cylinder and an oscillating delivery arm shaft, said impression cylinder rotating during reciprocation of the type bed in a printing direction except in the absence of a sheet on the cylinder or in the event of an improperly registered sheet in which case the cylinder remains stationary, the combination with a control shaft for controlling the operation of the press and which is spring tensioned into a stop position, friction locking means for holding the control shaft in selected positions, handle means adapted to be manually actuated for sequentially releasing the locking means and rotating the shaft, a trip lever having a part operatively associated with the handle means, said part upon movement in a certain direction effecting release of the said locking means, actuating means adapted to contact the trip lever under conditions when the cylinder remains stationary during reciprocation of the type bed in a printing direction, said contact of the actuating means With the trip lever effecting a rocking of the lever to cause movement of said part, said actuating means during printing operations of the press having compound movement in directions approximately at right angles to each other, and said compound move ment being produced partly by the oscillations of the delivery arm shaft and partly by the rotations of the impression cylinder, a positionable control bar having associated relation with the trip lever and with. the actuating means, said control bar when located in one position permitting the actuating means to contact the trip lever in the event the cylinder remains stationary during reciprocation of the type bed in a printing direction, and said control bar in a second position having such coaction with the actuating means and trip lever as to we vent contact of the actuating means with the trip lever even though the cylinder remains stationary during a reciprocation of the type bed in a printing direction, and trip reset means operating automatically due to the rotations of the impression cylinder for releasing the control 0 bar when the bar is located in the said second position.

5. In a printing press of the type having an intermittently rotatable impression cylinder adapted to rotate during the impression portion of each printing cycle if a properly registered sheet is presented thereto, but which is adapted to remain stationary during said portion of the cycle if a properly registered sheet is not presented thereto, the combination of automatic tripping means for stopping the press upon non-rotation of the impression cylinder during the impression portion of a printing cycle including a pivotally mounted trip lever, and actuating means responsive to non-rotation of said cylinder for moving said trip lever to a tripping position, manually operable control means for rendering said actuating means inoperative to move said trip lever whereby said press can be operated for make ready purposes although no sheets are presented to said impression cylinder and thus said cylinder remains stationary during the impression portion of the printing cycle, and automatic reset means adapted to be actuated by said actuating means upon the presentation of a sheet to and subsequent rotation of the impression cylinder to thereby render said actuating means operative to move said trip lever to its tripping position upon non-rotation of the impression cylinder during the impression portion of a subsequent printing cycle.

6. In a printing press having an impression cylinder which is adapted to rotate during the impression portion of each printing cycle if a registered sheet is presented thereto but which is adapted to remain stationary during the impression portion of the cycle if a properly registered sheet is not presented thereto, the combination including a manual control lever which is movable from a stop position to start the press and thereafter maintain the press operating at a predetermined speed, means biasing the control lever to a stop position, releasable means for holding said lever in a selected position, a trip lever having an operating and a tripped position, an oscillating shaft spaced from said trip lever, a link connected to said shaft in a manner that one end of said link normally reciprocates in a path which intercepts the trip lever, an eccentric mounted for rotation with the impression cylinder, a rod having a connection with said eccentric and with said one end of said link whereby upon rotation of the impression cylinder and therewith the eccentric said rod displaces the said one end of the link from its normal intercepting path whereas, upon non-rotation of the impression cylinder the rod permits the said one end of the link to follow said intercepting path to thereby move the trip lever from the said operating position to the tripped position, and means actuated by movement of said trip lever for releasing said releasable means to permit the control lever to return to its stop position under the influence of said biasing means.

7. In a printing press having an impression cylinder which is adapted to rotate during the impression portion of each printing cycle if a registered sheet is presented thereto but which is adapted to remain stationary during said impression portion of the cycle if a registered sheet is not presented thereto, the provision of means for stopping the press if the impression cylinder fails to rotate during the impression portion of a printing cycle including a pivotally mounted trip lever, an oscillating shaft spaced from said trip lever, a link connected to said oscillating shaft in a manner that one end of said link normally reciprocates in a path which intercepts the trip lever, a rod, an eccentric mounted for rotation with the impression cylinder, said rod having a connection with said eccentric and with said one end of the link, whereby upon rotation of the impression cylinder and therewith the eccentric said rod displaces the said one end of the link from its normal path whereas, upon non-rotation of the impression cylinder the rod permits the said one end of the link to remain in said path to thereby intercept the trip lever and thus stop the press, a positionable 8 7 control bar mounted adjacent said link, said control bar having a first position wherein it is clear of said link and a second position wherein it prevents said link from engaging the trip lever upon non-rotation of the impression cylinder, and manual means for moving said control bar between said first and second positions.

8. In a printing press, the combination as defined by claim 7, additionally including trip reset means, said trip reset means including a lever yieldingly biased in a direction to engage and hold the control bar in said second position after the control bar is manually located in said position, a pin movable with said rod, and a member on said lever adapted to be engaged by said pin upon movement of the rod as a result of the rotation of the impression cylinder for releasing the lever from its holding relation with the control bar.

9. In a printing press of the class having a vertically reciprocated type bed, an intermittently rotatable impression cylinder, said cylinder being adapted to rotate during the impression portion of each printing cycle if a registered sheet is presented thereto whereas it is adapted to remain stationary during the impression portion of the cycle if a registered sheet is not presented thereto, and an oscillating delivery arm shaft, the combination including a positionable control shaft for controlling the starting, stopping and running speed of the press, means biasing said control shaft toward a stop position, friction locking means for securing the control shaft in a selected position, handle means on the control shaft for manually releasing the locking means and moving the control shaft to a selected position, a trip lever having an arm extending adjacent the handle means, said arm being adapted to actuate the handle means upon movement of the trip lever to thereby release the locking means and permit the control shaft to return to the stop position under the influence of said biasing means, and actuating means for said trip lever including a link connected to the oscillating delivery arm shaft in a manner that one end of said link normally reciprocates in a path which intercepts the trip lever, an eccentric mounted for rotation with the impression cylinder, a rod having a connection with said eccentric and with the said one end of the link whereby upon rotation of the impression cylinder and therewith the eccentric said rod displaces the said one end of the link from its normal reciprocating path whereas, upon non-rotation of the impression cylinder said rod permits the said one end of the link to remain in said path so that it will intercept and move the trip lever.

10. In a printing press, the combination as defined by claim 9, wherein the friction locking means includes two sets of friction discs in alternating relation, one set being non-rotatably fixed to the control shaft and the other set being non-rotatably fixed to the journalling frame for the control shaft.

11. In a printing press, the combination as defined by claim 9, additionally including a positionable control bar pivotally mounted adjacent the actuating means, said control bar having a first position wherein it permits the actuating means to engage the trip lever upon non-rotation of the impression cylinder and a second position wherein it prevents the actuating means from engaging the trip lever upon non-rotation of the impression cylinder, and means for moving the control bar between said first and second positions.

References Cited by the Examiner UNITED STATES PATENTS WILLIAM B. PENN, Primary Examiner. 

1. IN A PRINTING PRESS OF THE CLASS HAVING AN INTERMITTENTLY ROTATING IMPRESSION CYLINDER AND AN OSCILLATING DELIVERY ARM SHAFT, THE COMBINATION INCLUDING A PIVOTED TRIP LEVER YIELDINGLY HELD AGAINST A STOP PREVENTING ROTATION OF THE TRIP LEVER IN ONE DIRECTION, A TRIP ARM PROVIDED BY THE LEVER AND HAVING MOVEMENT WHEN THE LEVER IS ROCKED IN AN OPPOSITE DIRECTION, A CONTROL SHAFT FOR STARTING AND STOPPING THE PRESS AND FOR CONTROLLING PRESS SPEED, SAID CONTROL SHAFT BEING SPRING TENSIONED INTO A STOP POSITION, FRICTION MEANS FOR LOCKING THE CONTROL SHAFT IN SELECTED POSITIONS WHEN RENDERED OPERATIVE AND FOR RELEASING THE CONTROL SHAFT FROM ITS SELECTED POSSITION WHEN THE FRICTION MEANS IS RELEASED, MANUAL MEANS FOR LOCKING AND RELEASING THE FRICTION MEANS, SAID TRIP ARM HAVING ASSOCIATION WITH THE MANUAL MEANS IN A MANNER TO EFFECT RELEASE OF THE FRICTION MEANS WHEN THE TRIP LEVER IS ROCKED IN SIAD OPPOSITE DIRECTION, ACTUATING MEANS RESPONSIVE TO NON-ROTATION OF THE IMPRESSION CYLINDER FOR ROCKING THE TRIP LEVER IN SAID OPPOSITE DIRECTION, MEANS OPERATIVELY CONNECTING THE ACTUATING MEANS WITH THE IMPRESSION CYLINDER AND WITH THE DELIVERY ARM SHAFT, WHEREBY SAID ACTUATING MEANS HAS COMPOUND MOVEMENT DURING PRINTING OPERATIONS OF THE PRESS, SAID COMPOUND MOVEMENT BEING PRODUCE PARTLY BY THE OSCILLATION OF THE DELIVERY ARM SHAFT AND PARTLY BY THE ROTATION OF THE IMPRESSION CYLINDER, AND WHEREBY SAID ACTUATING MEANS IS OPERATIVE TO CONTACT AND ROCK THE TRIP LEVER IN SAID OPPOSITE DIRECTION SHOULD THE IMPRESSION CYLINDER FAIL TO ROTATE DURING AN OPERATION WHICH COULD OTHERWISE CONSTITUTE A PRINTING OPERATION. 